KTDRR Research Evidence Training: An Overview of Effect Sizes and Meta-analysis

About the Webcast

Systematic review and meta-analysis are techniques used to synthesize and summarize large bodies of research literature. Compared to results from a single primary study, meta-analysis provide greater generalizability, increased precision, and the ability to explore heterogeneity across studies (Borenstein, Hedges, Higgins, & Rothstein, 2010; Pigott, 2012). In this Webcast, we will provide participants with an overview of the foundation of meta-analysis, an effect size, which is a quantitative indicator of a treatment effect or relation between two variables. We will also explicate the basic processes of a meta-analysis and how the technique can be used to answer complex questions asked by policymakers and practitioners.


Presentation Materials: (Archive Coming Soon)


About the Presenters

Photo of Ryan Williams

Ryan Williams, PhD, is a principal researcher at AIR and leads large-scale evaluations and research syntheses. Dr. Williams’ work focuses on improving generalizations in education research through research synthesis. He is currently the PI on an IES meta-analysis that is exploring sources of heterogeneity in mathematics intervention effects. He also is a co-PI of an IES methods training institute for advanced meta-analysis. Dr. Williams is Associate Methods Editor of The Campbell Collaboration Education Coordinating Group.


Photo of Joshua Polanin

Joshua Polanin, PhD, is a principal researcher at AIR who has experience in the application and use of quantitative methodology in criminal justice, education, and behavioral health. He is the PI of two National Institute of Justice–funded systematic reviews and meta-analyses and the co-PI of one IES-funded systematic review and meta-analysis. In addition, he currently serves as the project director for the WWC’s Statistics, Website, and Training (SWAT) contract and is co-PI of an IES methods training institute for advanced meta-analysis. Dr. Polanin is also active in The Campbell Collaboration and served as an Associate Editor of the Methods Group.